1. Field of the Invention
The present invention generally relates to electrical connectors, and more particularly to an insulation displacement connector used to connect electrical wiring, the connector having a conformable sealing material which flows around the wires as the connection is made.
2. Description of the Prior Art
Insulation displacement connectors (also known as solderless electrical connectors) are known in the art, and are used to interconnect conductors which have an outer insulating layer. These devices typically include a central body or housing having one or more channels therein for receiving the conductors, and a U-shaped metallic contact element which provides the electrical connection between the conductors. As an insulated conductor is placed in the slot defined by the U-element, the inner walls of the slot cut away the outer insulating layer (hence the term "insulation displacement"), and make contact with the central metal wire. An early version of such an insulation displacement connector (IDC) is shown in U.S. Pat. No. 3,202,957 issued to E. Leach, which has an M-shaped element, i.e., there are two parallel slots in the element for receiving the two wires to be interconnected.
The prior art is replete with variations in the structure of the bodies and contact elements used in insulation displacement connectors. Some of these are shown in the following U.S. Pat Nos.:
______________________________________ U.S. Pat. No. Inventor(s) ______________________________________ 3,189,863 E. Leach 3,258,733 R. Elm 3,388,370 R. Elm 3,500,292 Enright et al. 3,573,713 Enright et al. 3,576,518 Bazille et al. 3,605,072 A. Driscoll 3,609,644 W. Seim 3,656,088 W. Seim 3,723,948 Wyatt et al. 3,793,611 Johansson et al. 3,793,612 A. Driscoll 3,845,236 G. Anderson 3,858,157 J. Bazille 3,869,190 J. Bazille 3,912,356 R. Johansson 3,949,467 Mayala et al. 4,124,265 F. Turk 4,326,767 Silbernagel et al. 4,444,448 Silbernagel et al. 4,444,449 Aysta et al. 4,496,206 Markwardt et al. Des. 191,399 E. Leach ______________________________________
Due to the fact that the contact element displaces the insulation only where the element itself contacts the metal wire, very little of the metal wire is exposed. While this is adequate for some applications, it has been found that the contact element/wire interface often corrodes due to permeation of moisture into the IDC, resulting in a failure of the connector. This problem may be overcome by filling the connector with a sealant, such as silicone grease, prior to making the connection, as suggested in U.S. Pat. No. 3,804,971 issued to J. Bazille. Of course, filling the connector with grease adds an extra step in use of the device, and requires the user to carry a supply of the grease. Even if the grease were placed in the connector at the factory, the Bazille device suffers an additional disadvantage in that there is no guarantee that the grease will be guided to a specific location, e.g., about the connection interface, since there is no defined path for the grease to follow. In other words, an excess amount of grease must be placed in the cavity of the base in order to insure that all voids within the connector are filled. This may result in the overflow of excess grease, which is undesirable.
It would be preferable to initially provide a sealing material within the connector, avoiding the separate step of filling the connector with an insulating grease. This is the approach taken in U.S. Pat. No. 3,410,950 issued to W. Freudenberq. The connector shown in that patent is an open ferrule having sidewalls which are bent and depressed over the conductors. As the conductors are seated in the contact elements, a film is ruptured, allowing sealant to flow around the connection.
The primary disadvantage of this article is that it requires the use of a special (i.e., expensive) crimping tool. Moreover, the construction of the article is complicated by the vacuum-forming and heating process used to apply the film to the article, which also contributes to extra expense of the finished item. Finally, the flow of sealing material depicted in Freudenberg is idealized, and the material often does not completely surround the connection (see col. 5, lines 33-40). As can be seen in FIG. 4 of that patent, it is nearly impossible for sealing material to flow above the wire (it is restricted by the film barrier), leaving the connection vulnerable to corrosion from moisture permeation. It would, therefore, be desirable and advantageous to devise an insulation displacement connector having a conformable sealing material which does not require the use of any special tools, which has a simplified construction, and which has improved sealing ability.
Accordingly, the primary object of the present invention is to provide an insulation displacement connector for interconnecting electrical wiring.
Another object of the invention is to provide such an insulation displacement connector having an internal sealant.
Still another object of the invention is to provide an insulation displacement connector in which the sealant flows about the conductor or encapsulates the junction between the wire and contact element to completely protect the connection from environmental influences.
Yet another object of the invention is to provide a sealed insulation displacement connector which may be used without the assistance of any special tools.